Boxes are made from 20mm white American Oak. This wood provides a much greater degree of protection from the British weather. The front joints are dove-tailed to provide a more secure and longer lasting joint. Most other joints are further held together using Miller Dowels rather than screws. All joints are glued on assembly.
As with the pine boxes, the roof is pitched at a steep angle to help prevent other birds from perching on the box. And there is a rain drip channel cut into the box lid to prevent water from entering into the box. The roof has a long front overhang and is hinged at the back by a brass hinge.